Complete deletion / formatting of a Debain 11 server

Hey guys,

What I need to know: We run our servers with Debian 11. As soon as a project is finished, I would like to completely format the server, i.e. kill it completely. I know that there are special ISO's that you can mount or commands for the console, but unfortunately I can't find them anymore.

Anyone have anything to format a Debian server completely securely and irretrievably? The formatting process can take several days, that's no problem.

I will pay for your help.

You dont need anything more than that:
https://wiki.archlinux.org/title/Securely_wipe_disk